Add the Geant4 Monte Carlo radiation transport toolkit and its Python bindings.
update bud to 0.32.0 (WIP)
update google music-manager
update links
Allow ansible to install on darwin platforms

I am using this package on my Yosemite install of OS X and it works great. It also pretty closely follows the Homebrew recipe that most OS X users use, so I think we can open it up to other OS X users.
Update to latest ansible version
Removed all versions of geant4 except for the latest one.
postgresql: use configured port when invoking psql
elixir: make curl available to mix
New python package: restview-2.1.1
fix double slash in mix binary path
Apache Cassandra 2.1.0
qbittorrent: disable parallel building due to failures
giflib: add back the 5.0 version

Should fix tracker and may be used to fix
other packages after commit 61f8cee.

Untested as it takes too much time to recompile
everything these days.
Merge pull request #4357 from flazz/master

new: Apache Cassandra 2.1.0
Merge pull request #4354 from k0ral/restview

New python package: restview-2.1.1
Merge pull request #4298 from daogames/tb/elixir-mix-curl-fix

elixir: make curl available to mix
Merge pull request #4294 from daogames/tb/psql-port-fix

postgresql: use configured port when invoking psql
giflib: default to 5.0.5

5.1.0 apparenlty breaks a bunch of stuff, see comments on
https://github.com/NixOS/nixpkgs/commit/61f8cee6ce16ed8c312cc86a987c35f014c0a36e
geany: Update from 1.23.1 to 1.24.1

Closes #4359